Device for opening and closing a passage orifice present in a housing

ABSTRACT

A device for opening and closing a passage orifice provided in a housing, the housing having a supply duct leading to the passage orifice and a discharge duct following the passage orifice, with a closing body which opens and closes the passage orifice and determines the throughflow quantity of a heating medium which is provided for heating a medium which surrounds the device, the closing body being activated by an actuation element which comprises a thermal head having a space filled with a gaseous medium and closed by means of a diaphragm.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a device for opening and closing a passage orifice present in a housing, with a closing body which opens and closes the passage orifice and determines the throughflow quantity of a heating medium provided for heating a medium which at least partially surrounds the device.

2. Description of Related Art

A device of this type is used, for example, as part of a washing-water container heating for motor vehicles. As a result, the windscreen-wiping water is prevented from freezing in cold months and the use of frozen windscreen-wiper water is prevented.

Wax expansion elements are already known, which are used for washing-water container heatings of this type, in order to heat the washing water to a desired temperature and keep it thermally controlled. These wax expansion elements have a housing portion in which the wax is provided. As soon as a cooling of the wiping water and therefore of the wax occurs, the wax changes to a solid form, with the result that reduction in volume takes place. A valve is opened via a piston, so that a heating medium can be flow through the valve and it becomes possible for the wiping water in the washing-water container to be heated. As soon as a set temperature is reached, the valve closes.

These wax expansion elements for the control of hot-water container heatings have the disadvantage that high forces are built up during the liquefaction of the wax, the result of which is that an overcompensation of the closing movement of the valve is required in order to prevent a break-out of the housing parts or damage to the housings and inoperability. At the start of the heating period, these elements have high inertia, and, at the end of the heating period, there is the problem of the forces which build up sharply and which may result in damage to the housing. Overlift compensation is therefore necessary. This leads to a larger construction space.

BRIEF SUMMARY OF THE INVENTION

The object on which the invention is based is, therefore, to provide a device for opening and closing a passage orifice present in a housing, the said device allowing a sensitive regulation of a passage orifice for a heating medium and being cost-effective in terms of production.

This object is achieved, according to the invention, by means of the features of the device for opening and closing a passage orifice provided in a housing, the said housing having a supply duct leading to the passage orifice and a discharge duct following the passage orifice, with a closing body which opens and closes the passage orifice and determines the throughflow quantity of a heating medium which is provided for heating a medium which at least partially surrounds the device, characterized in that the closing body is activated by an actuation element comprising a thermal head having a space filled with gaseous medium and closed by means of a diaphragm. The further advantageous refinements and developments of the invention are specified in the further dependent claims.

The device according to the invention has the advantage that, in order to control the throughflow quantity flowing through a passage orifice, a closing body is provided, the opening and closing movement of which is activated via an actuation element comprising a thermal head having a gas-filled space which is closed by means of a diaphragm. Activation is thereby afforded, in which the control of the throughflow quantity becomes possible at least within a state of aggregation of the sensor medium. Furthermore, by the closing body being integrated at least partially on or with the thermal head, a compact type of construction is afforded. Owing to the use of the thermal head as an actuation element, overcompensation during a closing movement is not required, as compared with wax expansion elements known hitherto. As a result, the structural unit can be simplified and can therefore be produced cost-effectively.

According to an advantageous refinement of the invention, there is provision for the closing body to be provided, in the direction of flow of the heating medium, in a regulating space which follows the passage orifice and from which the discharge duct branches off. This arrangement and refinement affords a compact type of construction. In addition, the thermal head may be adjacent to the regulating space or at least partially engage into this. At the same time, it becomes possible for the arrangement of the at least one supply duct and at least one discharge duct to have the configuration of a corner version, in which the discharge duct and the supply duct are arranged at right angles to one another. This refinement likewise makes it possible also to have a parallel version in which the supply duct and the discharge duct are arranged so as to run parallel in the housing or their connection orifices are oriented parallel to one another.

The closing body of the device advantageously has a guide portion which is received by a housing portion of the thermal head. A reduction in the components can thereby be achieved, since the thermal head has to be fastened to the housing and this fastening portion advantageously at the same time forms, on the inner circumference, the housing portion which guides the closing body.

Advantageously, furthermore, there is provision for the closing body to be arranged perpendicularly to the diaphragm which is provided in the thermal head. A maximum force effect can thereby act on the closing body via the diaphragm. Thus, even slight changes of the gas volume in the thermal head can be transmitted to the opening and closing travel of the closing body.

For the maximum transmission of closing force to the closing body via the diaphragm, there is advantageously provision for an end face of the closing body, the said end face pointing toward the diaphragm, to comprise at least one third of the area of the diaphragm face. The area and the pressure are proportional to one another for force transmission, with the result that this arrangement allows high force transmission and therefore a reliable closing of the passage orifice.

According to an advantageous refinement of the invention, there is provision for the closing body to have a shoulder which delimits the guide portion and which engages behind the housing portion receiving the guide portion. The closing body can thereby be held captive in the thermal head, thus affording simple and rapid assembly.

To protect the thermal head, there is advantageously provision for the closing body to have at least one annular element which is arranged between the thermal head and a discharge duct branching off from the regulating space. This element not only assumes a protective function, but can also at least seal off the regulating space. At the same time, this annular element may also serve for assisting the guidance of the closing body in the thermal head.

Alternatively, there may also be provision for the regulating space to have a guide portion which cooperates with a guide portion of the closing body. As a result, a guide portion in the thermal head may be dispensed with or be additionally provided.

The sealing element on the closing body, the said sealing element delimiting the regulating space, is advantageously received in a peripheral groove and is designed as an annular element. Advantageously, heat-resistant O-ring seals are provided, the material of which is adapted to the type of heating medium and to the ambient temperature.

Furthermore, there is advantageously provision for the thermal head to be positioned on the housing with respect to the regulating space, at least one sealing element being interposed. Further leaktightness is thereby achieved. At the same time, this sealing element, which is preferably designed as an O-ring seal, may serve as an anti-twist device, in order to prevent an unwanted release of the thermal housing.

According to an advantageous development of the invention, the closing body has a closing face which points towards the passage orifice and which bears against the valve seat of the supply duct. This closing face may lie in an end face of the closing body, the said end face being formed parallel to the passage orifice, so that the closing body bears to blocking against a shoulder of the passage orifice and closes the passage orifice. Alternatively, there may also be provision for the closing face and a valve seat in the passage orifice to be of stepped, conical or tapered design or to be designed as ball valve. A sealing-off arrangement can thereby be afforded. In addition, the closing body is guided and centred in a closed position.

For the simple arrangement and compact configuration of the device, there is provision for the closing body advantageously to be of 1-part design, to have a guide portion for arrangement in the thermal head and to comprise, opposite the latter, a closing face pointing toward the passage orifice. This can give rise to a reduction in the components and to a direct force transmission which leads, in turn, to a sensitive opening and closing movement.

For opening the passage orifice, the closing body preferably has a regulating element which operates counter to the thermal head. This regulating element is advantageously designed as a regulating spring or opening spring.

According to first advantageous embodiment of the closing body, there is provision for this regulating element to be provided in the regulating space and to surround a reception portion of the closing body, the said reception portion being provided between a closing face and a guide portion of the closing body. The regulating element engages, for example, on a shoulder which surrounds the passage orifice or is adjacent thereto, and is supported, near the guide portion of the closing body, on a further shoulder.

According to an alternative embodiment of the closing body, there is provision for the regulating element to engage on an end face of the closing body, the said end face being assigned to the passage orifice, the regulating element in this case being arranged in a chamber of the supply duct. This embodiment allows a compact elongate to tubular configuration, whereas the first alternative embodiment makes it possible to have a very small and compact embodiment in terms of overall dimensions.

Advantageously, to set the device or the valve for opening and closing the passage orifice, there is provision for at least the diaphragm, the gas or sensor medium or the regulating element to be coordinated with one another and to be adapted to the heating temperature of the medium surrounding the device, so that the heating of the medium is ensured. In addition, the diaphragm face or the end face of the closing body may also be taken into account in order to achieve an opening movement of the valve only beyond a defined temperature or in order to provide a minimum force for maintaining the closing position of the closing body.

The closing body is preferably produced from a thermally non-conductive material. A reliable closing function can thereby be ensured.

Plastic or a composite plastic material may be used, which constitutes a cost-effective solution. Alternatively, ceramic or similar materials may also be used for producing the closing body.

According to a first advantageous embodiment, there is provision for the housing to be produced from a material having low thermal conductivity. For this purpose, in particular, ceramic material or composite material, plastic or a composite plastic material is provided. The housing can thereby be produced in a simple way as an injection moulding. In addition, insert parts may be provided in the housing for the connections of the supply and discharge lines for mounting on the supply and discharge duct, so that a cost-effective production of the housings is afforded in a two-component injection-moulding method. Alternatively, plug and/or snap connections may also be provided. When materials having low thermal conductivity are used, the housings are of small and compact design. The supply line advantageously has a spiral or helical configuration directly in front of the housing, in order to heat the medium by means of the heating medium.

According to an alternative embodiment of the housing, there is provision for using a material having high thermal conductivity. For example, metallic materials my be employed. Preferably, aluminium or aluminium alloys which have a low weight are employed. In this embodiment, the housing acts at the same time as a heating body, so that a direct supply of the heating medium via a supply line is afforded. These housings may likewise be of compact or slightly larger design, in order to serve as heating bodies and to have a heat storage capacity.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention and further advantageous embodiments and developments of this are described and displayed in more detail below with reference to the examples illustrated in the drawings. The features which are to be gathered from the description of the drawings may be applied, according to the invention, individually in themselves or severally in any desired combination. In the drawings:

FIG. 1 shows a diagrammatic illustration of an application example, using the device according to the invention,

FIG. 2 shows a diagrammatic enlarged sectional illustration of the device according to the invention,

FIG. 3 shows a diagrammatic enlarged illustration of an alternative embodiment of the device according to the invention,

FIG. 4 shows a diagrammatic enlarged sectional illustration of a further alternative embodiment of the device according to the invention,

FIG. 5 shows a diagrammatic enlarged sectional illustration of a further alternative embodiment of the device according to the invention,

FIG. 6 shows a diagrammatic enlarged sectional illustration of a further alternative embodiment of the device according to the invention,

FIG. 7 shows a diagrammatic enlarged sectional illustration of a further alternative embodiment of the device according to the invention, and

FIG. 8 shows a diagrammatic illustration of an alternative embodiment of the invention in an application example according to FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates diagrammatically an application example of the use of the device 11 according to the invention. This application example shows a washing-water container 12 which is filled with a liquid, oily or gel-like medium 14, for example with washing water, to the filling-level height illustrated. In the lower portion of the washing-water container 12, a line portion 16 is illustrated, from which the washing water is extracted and led to the intended location. The device 11 opens and closes a heating circuit for a heating medium which is led via a supply line 18 to the washing-water container 12 belonging to the device 11 and which is supplied to a heating source 21 via a discharge line 19. The heating source 21 may be a heat exchanger which is part of an engine block and through which cooling water flows. The heating source 21 may likewise be part of the interior heating for a vehicle, this illustrated heating circuit being supplied via a bypass line or the like. The device 11 is designed as a compact embodiment which is described in more detail in FIG. 2. For heating the washing water 14, the supply line 18 comprises a heating coil 22 in order to carry out the heat exchange.

The arrangement illustrated is only in principle. Its actual arrangement is adapted to the installation situation, and at the same time care is taken to ensure that the device 11 is positioned at as low a point as possible in a washing-water container 12, in order to control the heating even when there is only a slight residual quantity of washing water in the container.

The use of the device 11 is not restricted to washing-water container heating in motor vehicles. This device 11 may be provided in any containers for receiving a liquid, oily or gel-like medium, in which it is desirable for the stored medium to have a defined temperature or to be heated to a desired temperature.

FIG. 2 illustrates a diagrammatic full cross section of the device 11 according to FIG. 1.

A housing 26 has a supply duct 27 which has a passage orifice 29 leading to a regulating space 28. A discharge duct 31 branches off from the regulating space 28, merges into the outlet orifice 69 and issues into the connecting line 19. In the regulating space 28, a closing body 32 is provided, this comprises an end face 33 which bears to blocking against a shoulder 34. The shoulder 34 surrounds the passage orifice 29. The end face 33 at the same time comprises a closing face 36 which cooperates with the shoulder 34 and which forms a valve seat 37. Alternatively, the closing face 36 and the valve seat 37 may be of stepped, conical, unilaterally or bilaterally wavy or such like design. Furthermore, there may be provision for the closing body 32 to comprise as closing face 36 a valve ball which bears, centred, in the valve seat 37.

Opposite the end face 33 of the closing body 32, the closing body 32 has a shoulder 39 which delimits a guide portion 41 of the closing body 32. The shoulder 39 is arranged within an actuation element designed as a thermal head 42 and is assigned to an end face 43 adjoining a housing portion 46 which guides the guide portion 41 of the closing body 32. The shoulder 39 is arranged at least with a slight clearance in a closing position of the closing body 32. This housing portion 46 of the thermal head 42 has at the same time, on its outer circumference, a fastening portion 47, via which the thermal head 42 is positioned with respect to the housing 26, for example by means of a screw connection.

The regulating space 28 is sealed off via a sealing element 48 which is provided between the housing 26 and the housing portion 46 of the thermal head 42. The guide portion 41 of the closing body 32 is designed cylindrically. Alternatively, there may also be provision for guide regions to be provided in the form of portions. In addition, an anti-twist device may be arranged, in order to achieve an exclusive axial movement of the closing body 32.

The guide portion 41 is delimited with respect to the regulating space 28 by means of an annular element 51 which may have sealing and/or guiding properties. This element 51 is designed as an O-ring seal and is arranged in a groove 52. This element 51 serves at least for the prevention of deposits of dirt on the guide portion 41. In addition, there may be provision for a groove or flute, serving for forced ventilation, to be provided on the guide portion 41 and/or in the housing portion 46.

Between the guide portion 41 and the end face 33 of the closing body 32, a reception portion 54 is provided, which is designed for receiving a regulating element 56. This regulating element 56 is provided as a regulating spring or opening spring and allows the opening movement of the closing body 32 in the direction of the thermal head 32. The regulating element 56 may additionally comprise setting discs, such as, for example, washers or annular spacer elements, in order to vary the opening force of the regulating spring. The opening force of the regulating spring is increased by the addition of setting discs, and vice versa.

The thermal head 42 comprises a diaphragm 58 which closes a space 59 filled with a medium 61. This filling takes place, for example via the filling tube 62 or by means of further filling techniques, with the result that an exact setting of the opening temperature or opening force for the closing body 32 can be carried out.

An end face 44 of the closing body 32 extends at least over one third of the diaphragm face, preferably over as large a fraction of the diaphragm face as possible, in order to achieve optimum force transmissions. The end face 44 bears against the diaphragm 58. The diaphragm 58 is produced from metallic material. The diaphragm 58 may advantageously be provided with a heat-insulating layer on the side pointing towards the closing body 32, so that the opening temperature and therefore the opening time point of the valve are not influenced by the heating medium in the regulating space 28.

The thermal head 42 is surrounded by the medium 14 to be heated. As soon as the predetermined temperature of the medium 14 is undershot, the gaseous medium 61 in the space 59 cools. A reduction in volume thereby takes place, with the result that the diaphragm can move resiliently towards the space 59. The regulating element 56 assists the opening movement of the closing body 32 which is enabled by the diaphragm 58, with the result that heating medium flows through the passage orifice 29 via the supply line 18. After the medium 14 has the desired or set temperature, because of the heating of the medium 61, which changes at least partially, preferably completely, from the liquid to the gaseous state, and because of its resulting volume expansion, an adjusting movement of the closing body 32 towards the passage orifice 29 takes place. The passage orifice 29 is closed. On account of the gaseous medium 61 in the space 59, which is present in evaporated form and exerts a limited residual closing force, there is no further increase in the closing force, as compared with wax expansion elements. During the rise in the evaporation temperature, there is no longer virtually any increase in pressure in the gaseous state. Long-lasting and reliable functioning is thereby ensured.

The housing 36 has, for example, depressions 64, 66 which are provided for the reception of connecting elements, in order to fix the supply line 18 and discharge line 19 to the housing 26. These connecting elements make it possible that those ends of the supply and discharge lines 18, 19 which are positioned in an inlet orifice 68 and an outlet orifice 69 allow, without threads, media-tight bearing contact and reception. This affords a cost-effective connection possibility. Alternatively, for example when the housing 26 is designed as an injection moulding, there may be provision for insert parts or connecting elements to be integrated in the housing 26.

The embodiment illustrated in FIG. 2 is illustrated as what is known as a corner version, that is to say the supply duct 27 is arranged at right angles to the discharge duct 31. Further relative arrangements of the supply and discharge ducts 27, 31 may be selected as a function of the installation situation. The supply and discharge ducts may likewise be interchanged in terms of their function.

FIG. 3 illustrates an alternative embodiment to FIG. 2. This embodiment differs from the embodiment according to FIG. 2 in that the supply and discharge ducts 27, 31 are arranged parallel to one another. One or other version may be advantageous as a function of the installation situation.

FIG. 4 illustrates an alternative embodiment to FIG. 3. In this embodiment, the regulating element 56 is provided in a chamber 71 of the supply duct 27. The regulating element 56 engages on the end face 33 of the closing body 32 and is positioned in an annular groove 72. The reception portion 54 is thus displaced into the end face 33 of the closing body 32. The closing body 32 positioned in the regulating space 28 has an outer circumference which is designed to be only slightly smaller than the diameter of the regulating space 28, so that only a small quantity of heating medium is provided in the regulating space 28.

In the embodiment of the housing 26 as a heating body, for example by means of a material having high thermal conductivity, there may also be provision for the closing body 32 to be designed with a small volume in a region between the closing face 36 and the guide portion 41, so that the regulating space 28 has a large reception volume for the heating medium, so that heat can be emitted for a longer period of time.

FIG. 5 illustrates a further alternative embodiment to FIGS. 2 and 3. In this embodiment, the closing body 32 has an end face 33 comprising an annular elevation 35 which bears against the shoulder 34 in order to form a valve seat 37. The annular elevation 35 is of semicircular, V-shaped or hump-shaped design, as seen in cross section, or preferably has a rounding as a closing face 36, with the result that a small sealing face is formed. This arrangement has the advantage that a better leak tightness can be achieved, since this closing face 36 having the annular elevation 35 is susceptible to only a slight extent to soiling. For example, the closing face designed a rounding 36 has a radius of 0.1 mm to 10 mm. The flanks adjoining it may be arranged in a V-shaped manner with respect to one another and, for example, form an angle of 30°to 160°.

Owing to the alternative configuration, a type of linear or small-area closing face 36 is afforded by the rounding, instead of a closing face 36 bearing in a planar manner against the shoulder 34.

The valve seat illustrated in FIG. 5 may also be provided mirror-symmetrically, so that the elevation 35 is arranged on the shoulder 34 of the housing 26 and the end face 33 is, for example, of planar design. As further alternative embodiments of a valve seat 37 of this type, there is provision for the elevation 35 not to be designed annularly, but to comprise other geometries which may be adapted correspondingly to the geometry of the passage orifice 29. The elevation 35 may comprise a planar end face, a curved face, a semicircular or quarter-circle face or else a face having a radius. The opposite face of the valve seat 37 may be designed identically or comprise a geometry deviating from this. At least a linear and/or small-area bearing contact is advantageous. In addition, the closing face 36 and the shoulder 34 may be designed with respect to one another in such a way that a centring function is afforded by the mutually contiguous faces of the valve seat 37. The geometry of the closing face 36 and shoulder 34 may be conceived according to the abovementioned examples or by any desired linear profiles adapted to one another.

The elevation 35 provided on the closing face 36 and/or on the shoulder 34 may be provided in one piece on the closing body 32 and the housing 26 or, for example, be designed as a separate part and be connected to the closing body 32 and/or the housing 26 non-positively and/or positively and/or in a materially integral manner. For example, an adhesive or press connection of insert parts which have the elevation 35 may be provided. As a result, for the configuration of the valve seat, materials other than for the closing body 32 and the housing 36 and which preferably fulfil the requirement of a long useful life may be used.

The device 11 illustrated in FIG. 6 constitutes an alternative embodiment to the preceding embodiments, and is designed, merely by way of example, as a parallel version. The closing body 32, has, on its end face a closing face 36 which is designed as a rounding. This rounding may be designed as a segment of a circle or else comprise an elliptic shape or a non-constant curvature. A shoulder 34 of the valve seat 37 has a complementary geometry to the closing face 36. Such a rounding of the closing face 34 may be of convex or concave design, the opposite closing face 36 being adapted. This refinement has the advantage that, after closing, the closing body 32 rests in a secured closing position and separates the passage between the supply duct 27 and the discharge duct 31. At the same time, such a refinement makes it possible to have a self-centring arrangement of the closing body 32 in the valve seat 37. According to an alternative refinement, there may be provision for one closing face to be rounded and for the opposite closing face to be of tapered or wedged-shaped design. Furthermore, alternatively there may be provision for one closing face to have a rounded and a tapered or wedge-shaped portion and to bear against an opposite shoulder which has at least one face portion for leaktight and centred reception.

This alternative embodiment has, furthermore, the advantage that, owing to a closing body 32 of shortened design, a compact configuration and a device 11 having a small build are achieved. In this embodiment the sealing element 51 and the associated groove 52 have not been provided. A reduction in parts may thereby become possible thus allowing a cost-effective configuration and rapid assembly of the device 11. This embodiment comprises only a housing 26, a closing body 32 arranged in the thermal head 42, a spring element 56 and a sealing element 48.

This shortened arrangement has, furthermore, the advantage that thermal separation takes place on account of narrow tolerances between the fastening portion 47 and the guide portion 41 of the closing body 32. A suitable opening characteristic can thereby be achieved, without an over-sensitive opening and closing of the valve being obtained.

Owing to the narrow tolerances, thermal separation with respect to the thermal head 42 and to the gaseous medium 61 provided in it can take place. As a result, the thermal head 42 or the gaseous medium 61 can be activated solely by the ambient temperature. The medium 61 provided preferably in the space 59 of the thermal head 42 changes its state of aggregation between liquid and gaseous. By the medium 61 being introduced under an intended pressure into the space 59, an opening characteristic adapted to the ambient conditions can be achieved.

FIG. 7 illustrates an alternative embodiment to FIG. 6. In this embodiment, the shoulder 34 is rounded concavely and the closing body 32 bears with a wedge-shaped or tapered closing face 36 against the shoulder 34. The arrangement of the wedge-shaped or tapered closing face 36 may be also be provided on the shoulder 34, in which case the closing body 36 has at its front end a concave rounding which bears against the wedge-shaped or tapered shoulder.

According to a further alternative refinement, there is provision for both the shoulder 34 and the closing face 36 to be designed concavely, thus affording a type of linear contact and sealing-off in the valve seat.

Both this device according to the invention and the further devices 11 described in FIGS. 1 to 7 have the advantage that they operate in an energy-free manner. Only the temperature difference in the surrounding region determines the opening and closing time point of the closing body 32. Such regions can be set and adapted, as desired, as a function of the type of filling medium and of the pressure in the space 59. In addition, an adaptation of the restoring spring 56 by means of the selected spring force may be advantageous. FIG. 8 illustrates a diagrammatic set-up similar to that of FIG. 1. Contrary to FIG. 1, the housing 26 is illustrated as a heating body and has, for example, an elongate tubular portion 76 which comprises the supply duct 27. A similar effect to that produced by the heating coil 22 can thereby be achieved. The configuration of this housing 26 makes it possible to arrange the regulating element 56 in the same way as in the embodiments according to FIGS. 2 and 3 or according to FIG. 4. The embodiment according to FIG. 4 may be modified to the effect that the supply duct 27 is arranged in the prolongation of the chamber 71.

The features described in relation to the individual exemplary embodiments are in each case essential to the invention themselves and may be combinable with one another in any way desired. 

1. Device for opening and closing a passage orifice provided in a housing, said housing having a supply duct leading to the passage orifice and a discharge duct following the passage orifice, with a closing body which opens and closes the passage orifice and determines the throughflow quantity of a heating medium which is provided for heating a medium which at least partially surrounds the device, characterized in that the closing body is activated by an actuation element comprising a thermal head having a space filled with gaseous medium and closed by means of a diaphragm.
 2. Device according to claim 1, characterized in that the closing body is provided, in the direction of the flow of the heating medium, in a regulating space which follows the passage orifice and from which the discharge duct branches off.
 3. Device according to claim 1, characterized in that the closing body has a guide portion which is received by a housing portion of the thermal head and the closing body is guided perpendicularly to the diaphragm.
 4. (canceled)
 5. Device according to claim 1, characterized in that the closing body has an end face which points towards the diaphragm and the size of which comprises at least one third of the diaphragm face.
 6. Device according to claim 1, characterized in that the closing body has a shoulder which delimits the guide portion and which engages behind the housing portion receiving the guide portion.
 7. Device according to claim 1, characterized in that the closing body has an annular element in a region between the discharge duct and the housing portion of the thermal head, the said housing portion having the guide portion.
 8. (canceled)
 9. Device according to claim 1, characterized in that the housing of the thermal head is positioned with respect to the regulating space, at least one sealing element being interposed on the housing.
 10. Device according to claim 1, characterized in that the closing body has a closing face which points towards the passage orifice and which bears against the shoulder and forms a valve seat on the supply duct and the closing face and the valve seat are of stepped or conical design or are designed as a ball valve.
 11. (canceled)
 12. Device according to claim 1, characterized in that the closing body is of one-part design and has a guide portion and a shoulder delimiting the latter and, opposite, a closing face pointing towards the passage orifice and the closing body, has, between the guide portion and the closing face a reception portion which receives a regulating element.
 13. (canceled)
 14. Device according to claim 1, characterized in that the closing body has, on an end face pointing towards the passage orifice, a reception portion, an annular groove, which is provided for receiving a regulating element which is arranged in a chamber of the supply duct. 15-16. (canceled)
 17. Device according to claim 1, characterized in that at least the diaphragm, the gaseous medium or the regulating element is adapted to the heating temperature of the medium surrounding the thermal head
 18. Device according to claim 1, characterized in that the closing body is produced from a material as ceramic, plastic or a composite plastic material having a low thermal conductivity.
 19. Device according to claim 1, characterized in that the housing is produced from a material as ceramic, from plastic as an injection moulding or from a composite plastic material having a low thermal conductivity.
 20. Device according to claim 19, characterized in that connecting elements for mounting the supply and discharge line of the heating medium are injection-moulded on the housing.
 21. Device according to claim 1, characterized in that the housing is produced from a thermally conductive material and is designed as a heating body.
 22. Device according to claim 1, characterized in that the closing face or the shoulder has an elevation for forming a valve seat, the said elevation bearing, opposite, against a shoulder or closing face and the shoulder or closing face opposite the elevation is designed as a planar bearing face, as a bearing face designed at least partially congruently to the elevation or as a bearing face designed at least partially identically or similarly to the elevation. 23-24. (canceled)
 25. Device according to claim 22, characterized in that the elevation is of V-shaped design, as seen in cross section, and its lateral flanks are arranged at an angle of 30° to 160°.
 26. Device according to claim 22, characterized in that a portion pointing towards the closing face or shoulder on the elevation has a rounding with a radius of 0.1 mm to 10 mm, a curved face, a semicircular or quarter-circle face or a planar face.
 27. Device according to claim 1, characterized in that the shoulder or the closing face of the closing body has a rounding which, in a closing position bears against a complementarily designed closing face or shoulder or against a wedge-shaped or tapered closing face or shoulder. 